Hydraulic pump and circuit system



Oct. l0, 1967 c. c. RENFROE HYDRAULIC PUMP AND CIRCUIT SYSTEM 2 Sheets-Sheet l Fild Aug. 6, 1965 INVENTOR CHA/2L Es c. Rf/vFaoE l BY n dan?, am

TTORNEYS` Oct. 10, 1'967 ;.v c. RENFRQE v HYDRAULIC PUMP AND CIRCUIT SYSTEM 2 Sheets-Sheet 2 Filed Aug. 6, 1965 B/ MORNE YS United 'States Patent O HYDRAULIC PUMP AND CIRCUIT SYSTEM Charles C. Renfroe, 709 N. Jefferson St., Albany, Ga. 31705 Filed Aug. 6, 1965, Ser. No. 477,881 7 Claims. (Cl. 60-52) ABSTRACT F THE DlscLosURE A hydraulic pump and circuit system in which a ram is displaced in a cylinder by tluid pressure supplied by the pump; the pump being at least partly immersed in hydraulic fluid. The pump i-s reciprocated by an eccentric so that iluid is pumped through4 a pressure line with the ports open to the iluid when the piston is at the extreme suction position, the ports then functioning to permit air to escape and to equalize pressure.

The present invention also relates to a pump having a piston with a novel cup and ring arrangement designed to prolong the life of the pump and to avoid early repair.

It is an object of the present invention to provide a hydraulic pump and system which has a unique pump design that eliminates entrapped air.

It is another object of the present invention to provide a hydraulic pump and system which are responsive to electric controls to displace a hydraulic ram in a cylinder which cylinder is in the circuit. l

It is still another object of the present invention to provide a novel immersion pump designed to be long lasting. without repair.

These and other objects will be apparent from the following description.

FIG. 1 is a plan view of the hydraulic pump.

FIG. 1A is an enlarged view from FIGURE '3 showing the piston, piston ring and cup assembly.

FIG. 2 is a side elevational view in section of the pump of FIG. l. f f y FIG. 3 is an enlarged sectional view illustrating the details of the pump assembly.

FIG. 4 is an enlarged sectional View showing the check valve assembly of the oil manifold.

Referring to the drawings, particularly FIGURE 2, the electrical connections include switch 1 to operate motor 4 through breaker switch 2 and starter solenoid 3.v A second switch 25 is connected to solenoid 50 and battery 101' supplies current to both circuits. The armature shaft 5 ofrmotor 4 is provided with an O-ring seal 7 in bushing 6 within tank 20. The armature shaft 5 is journalled to an eccentric cam 8 with a needle bearing keyed to the shaft which is supported in bushing 9 locatedl within the tank 20.

The details of the pump are shown in FIGURES 1A and 3 wherein the piston 10 reciprocates within sleeve through a bushing 11 threaded on the sleeve. A spacer 13 is mounted on the bottom of tank 20v and a piston return compression spring 12 is supported and retained between the spacer 13 and the head of piston 10. At Vleast one port 14 is provided in the sleeve and communication between the pressure and vacuum chamber 29 of the pump with uid in the tank is made during reciprocatiori of the pump. The lower extremity of the lpiston includes a cup 18 of neoprene, leather or other material conventionally used as deformable` washers and `including iron or steel that will cups in pumps. The cup 18 has a circumferential tapering edge 18a around its periphery adjacent the inner wall of sleeve 15. A ring 19 is mounted on piston 10 adjacent and above cup 18. Both cup 18 and ring 19 are retained by nut 19a threaded on the piston 10.

I-t will be apparent that as the piston is reciprocated the cup 18 will become worn since it bears against the cylinder wall. The chief reason for the wear is the pressure exerted on the cup during the pressure on down or compression stroke which presses the cup against the wall. This same pressure will continue to maintain the cups 18 in working condition during the pressure stroke. However, during suction stroke the tit of cup 18 will be relatively loose and the cup would normally need early replacement. However, ring'19 which is not subjected to pressure and excessive wear, continues to provide a snug t between the piston and sleeve during suction stroke so that early repair is unnecessary. Ring 19 can also be formed from leather or neoprene but is preferably formed of material having spring properties maintain close contact with the wall of sleeve 15. v

Referring now to the hydraulic circuit, tank 20 is preferably iilled with a hydraulic liquid having lubricating properties to a level near the armature 5. In any event, the liquid is above the ports 14 and tank 20 vacts as a Vreservoir for the hydraulic liquid. Suction intake 16a leads into chamber 29 through ball check valve 16 and spring 17. Pressure line 23 also provided with ball 21 and spring 22 leads to an oil manifold 32 shown in detail in FIGURE 4. Oil manifold 32 is provided Vwith three outlets or passageways to lines 23, 24 and 37. A ball 35 and spring 36 operate as a check valve to normally maintain lines 23 and 24 in communication. Plunger 33 surrounded by O-ring 34 which acts as 'a seal is mounted in the manifold to be displaceable to unseat ball 35 sothat line 37 can communicate with lines 23 and 24. f

Line 37 is a return line to the reservoir` or tank 20. Line 24 leads from the manifold to one end of cylinder 26 in which ram 28 comprising a piston and rod are iitted. Cylinder 26 and ram 28 are located substantially centrally at the lower end of the pump. v

Hydraulic uid under pressure flows through line-24 into one end of cylinder 26 to urge ram 28 tothe lef-t as seen in FIGURES l and 2.' If'plunger 33 unseats ball 35, springs 102 urge ram-28 to the right so that iluid is returned through line 24 to manifold 32jthe`n through return line 37 to tank 20. Springs 102,'quadrants 94 operate inthe same manner as the corresponding elements described in Patent No. 2,874,391. Line 38 leading from the upper end of cylinder 26 to the top ofl tank 20'is a breather'line and a bleed-oifin'the event of leakage in the ram.

` Pivotally connected to the end of ram 28 is a'c'am locking plate 56. One end of plate 56 is pivoted at :56a and axle 60 is keyed to hub 40,"both of which are secured to plate 56. At the other endof the plate a notch is provided to receive `sliding locking bar 72. The lower end of plate 56 has a sloping cam surface at 70. Support 30a for lockingrbar 72 holds solenoid 50 and also'mount's sliding collar `and a fixed collar 80a. Spring 82 biases collar *80 and bar tothe left as seenin' 'FIGURES V1 and 2 so that bar 72 engages notch 68. Sliding collar 80 is provided with arm 30 and an adjusting bolt 31. Boltl 31 is in alignment with thev forward end of plunger 3 33 so that when locking bar 72 and arm 30 slide to the right, contact between bolt 31 and plunger 33 is assured.

If the hydraulic pump and system are employed 'to operate a retractible running gear for a boat such as that described in Patent No. 2,874,391, the position of the various elements is shown in FIGURES 1 and 2 when the wheels are in ground engagement. That is, plate 56 is in locked position with locking bar 72 in slot 68. When the axle -60 is to be turned counterclockwise to raise the wheels, switch button 25 is pushed to energize solenoid 50 which withdraws bar 72. After bar 72 has cleared slot 68, bolt 31 engages plunger 33 and unseats ball 35 allowing hydraulic fluid to flow through line 24, manifold 32, return line 37, finally to tank 20. 'I'he force to urge ram 28 to the right and expel uid from cylinder 26 is springs 102 which operate on the quadrants 94 and axle 60 as described 'in Patent No. 2,874,391. Also, the weight of the boat assists the unloading of fluid and return of same to tank 20. After current has been dis,- continued spring 82 urges bar 72 and support 30a to their former positions.

When it is desired to lower the wheels or urge ram 28 to the left to the position seen in FIGURE 2, button switch 1 -is pushed and current from the battery circulates through breaker switch 2 (which remains closed until plate 56 is in lock position and adjustable locking screw 39 breaks contact in switch 2) to energize starter solenoid 3 so that motor 4 starts. Armature shaft 5 rotates so that eccentric 8 bearing on the top of piston 10 causes the piston to be reciprocated in sleeve 15.

O11 vthe upward yor suction stroke, hydraulic uid is drawn through intake 16a and ball 16 is unseated as spring 17 is depressed. When the piston has reached the position shown in FIGURE 3, ports 14 are opened so that pressure between chamber 29 and the interior of tank 20 is equalized. Ball 16 urged by spring 17 is then allowed to seat under normal spring pressure before any hydraulic pressure is exerted on the valve during down or pressure stroke. Thus equalization of pressure eliminates any pounding or chattering of the ball 16 in its seat and eliminates early repair or replacement of the valve parts.

During the compression stroke, pressure unseats ball 21 against spring 22 so that fluid is pumped through line 23 and uid ows to manifold 32 and line 24 leading to one end of cylinder 26. Ram 28 is urged to the left as seen in FIGURE 2, causing plate 56 to turn clockwise and pivot about axle 60 until locking bar 72 engages slot 68 in plate 56. Locking screw 39 engages a leaf in switch 2 to break the circuit and stop the motor 4 and the pump becomes inactive.

In 'the instant invention it will be appreciated that lubrication of the pumps moving parts as well as the bearing between the cam 8 and shaft 5 is assured. Also, no air can enter submerged ports 14. The pump itself can be described as a self-bleeding, self-priming, pressureequalizing, electrically driven cam-operated piston type hydraulic pump which is useful in a variety of applications where long life and economic maintenance are desired.

In one application, the present kinvention is adapted to be used to raise and lower wheels on a boat, as disclosed in FIGURE 1 of Patent No. 2,874,391. In this embodiment, the axle 60 in the instant application can be the same as shaft 60 in the aforementioned patent to which wheels that are mounted on cranks are carried. However, the unique features of the system, including the pump as well as the pump per se, make the pump useful in other applications. For instance, axle 60 could be any shaft turnably responsive to the displacement of a hydraulic ram.

The .foregoing detailed description has been given for clear-ness of understanding only of a single embodiment of the invention, and no unnecessary limitation should be understood therefrom, inasmuch as numerous modifications which do not affect the function of the invention will be obvious to those skilled in the art.

I claim:

1. A hydraulic pump and circuit system, including check valve means, a pump connected to said circuit, said pump including a reciprocating piston in a sleeve, said sleeve having a bleeding port in the side thereof to the piston chamber, said pump being at least partly immersed in oil whereby said port is below the oil level and in communication with said chamber during the suction stroke, said port being sealed and closed by said piston during compression stroke, means for reciprocating said piston to circulate hydraulic oil through said check valve means to a cylinder and a hydraulic ram in said cylinder displaceable responsive to the fluid pressure in said cylinder, wherein said hydraulic ram is linke-d to an axle through plate means whereby movement of said ram moves said plate means and rotates said axle.

2. The invention of claim 1, wherein said ram is connected to one end of said plate means and slidable locking means releasably engages the other end of said plate means whereby displacement of said locking means releases said plate means for movement.

3. The invention of claim 2, wherein said pump is reciprocated by electric motor means to pump oil through said circuit to said cylinder and said ram is displaced to move said plate means into locking engagement with said locking means, circuit breaking means mounted on said plate means to inactivate said motor when said plate means is engaged by said locking means.

4. The invention of claim 2, wherein said locking means is slideably connected to solenoid means whereby activation of said solenoid means slides said locking means out of engagement with said plate means.

5. The invention of claim 4, wherein said check valve means includes a seated ball check valve housed in an oil manifold, said manifold including a passage to a return line to the oil in which said pump is immersed, plunger means in said manifold for unseating said ball and permitting said oil to pass through said return line, means on said locking means for moving said plunger to unseat said ball when said solenoid means is activated and said locking means slides out of engagement with said plate means.

6. A hydraulic pump and circuit system, including check valve means, a pump connected to said circuit, said pump including a reciprocating piston in a sleeve, said sleeve having a bleeding port in the side thereof to the piston chamber, said pump being at least partly immersed in oil whereby said port is below the oil level and in communication with said chamber during the suction stroke, said port being sealed and closed by said piston during compression stroke, means for reciprocating said piston to circulate hydraulic oil through said check valve means to a cylinder and a hydraulic ram in said cylinder displaceable responsive to the uid pressure in said cylinder, wherein said check valve means including an oil manifold housing three passages, said hydraulic circuit system including vone circuit from said pump through two of said passages in said manifold to said cylinder, a second circuit in said system through the third passage in said manifold to a return line to the oil in which said pump is immersed, said third passage being normally closed by a seated ball valve when said piston is reciprocating, said pump being immersed in oil confined in a tank, an intake check valve in said tank leadng to said pump, a pressure line check valve leading from said pump to said manifold in said first circuit, whereby oil is sucked in from said tank and urged to circulate through said manifold to said cylinder by said reciprocating piston.

7. The invention of claim 6, wherein the hydraulic ram ispivotally connected to one end of said plate means and sliding locking means engages the opposite end of said plate means, solenoid means for sliding said locking 5 6 means out of engagement with said plate means, plunger References Cited means associated with said locking means for unseat- UNITED STATES PATENTS ing the ball closing said third passageway in said mani- 2 060 847 11/1936 Bowen 92 193 fold when said locking means is slid Out 0f engagement 2'828'170 3 /1958 Badgley "9 2 240 X with said plate means whereby oil in said circuit is 5 8855560 5 /1959 Ray 60 52 permitted to pass out of said third passageway through said return line to said tank. EDGAR W. GEOGHEGAN, Primary Examiner. 

1. A HYDRAULIC PUMP AND CIRCUIT SYSTEM, INCLUDING CHECK VALVE MEAN, A PUMP CONNECTED TO SAID CIRCUIT, SAID PUMP INCLUDING A RECIPROCATING PISTON IN A SLEEVE, SAID SLEEVE HAVING, A BLEEDING PORT IN THE SIDE THEREOF TO THE PISTON CHAMBER, SAID PUMP BEING AT LEAST PARTLY IMMERSED IN OIL WHEREBY SAID PORT IS BELOW THE OIL LEVEL AND IN COMMUNICATION WITH SAID CHAMBER DURING THE SUCTION STROKE, SAID PORT BEING SEALED AND CLOSED BY SAID PISTON DURING COMPRESSION STROKE, MEAN FOR RECIPROCATING SAID PISTON TO CIRCULATE HYDRAULIC OIL THROUGH SAID CHECK VALVE MEANS TO CYLINDER AND A HYDRAULIC RAM IN SAID CYLINDER DISPLACEABLE RESPONSIVE TO THE FLUID PRESSURE IN SAID CYLINDER, WHEREIN SAID HYDRAULIC RAM IS LINKED TO AN AXLE THROUGH PLATE MEANS WHEREBY MOVEMENT OF SAID RAM MOVES SAID PLATE MEANS AND ROTATES SAID AXLE. 